Aeration device

ABSTRACT

A soil aeration device may include a plurality of arcuate blades mounted to an assembly adapted to rotate and translate the blades proximate a ground surface, thereby forming aeration pockets in the soil. In certain embodiments, the arcuate tines penetrate and fracture the soil while minimizing the amount of soil lifted from the pocket deposited on the top of the soil. In various embodiments, a planetary gear assembly imparts to the tine a translational and rotational movement which creates a fractured pocket in the soil while minimizing the amount of soil lifted from the pocket and deposited on the surface of the soil. In still other embodiments, the arcuate tine may have mounted thereon a coring tube that cuts and removes a plug from the pocket formed in the soil.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 11/250,694, filed on Oct. 11, 2005, entitled “Aeration Device,”which is a divisional application of application Ser. No. 10/387,092,filed on Mar. 12, 2003, entitled “Aeration Device,” which claimspriority from U.S. Provisional Application No. 60/363,786, filed Mar.12, 2002, entitled “Aeration Device,” by David R. Maas, the entirety ofwhich are incorporated by reference herein.

BACKGROUND

Soil aeration devices are generally designed to cut a plug out of thesoil instead of driving a spike into the soil because the latterapproach compacts the soil. Towable soil aerator devices typicallyremove plugs of soil while forming an enlarged soil aeration pocket.Such aerators include hollow cylindrical tubes that enter the soil at anangle to cut free a cylindrical soil plug which contains grass, grassroots and soil. As the soil aeration device moves forward, planetarygears in the soil aeration device cause the soil aeration tubes to pivotto form a soil aeration hole or pocket wherein the bottom portion of thesoil aeration hole is larger than the top opening of the soil aerationhole. The soil aeration tube is then lifted out of the soil to removethe soil plug, which is usually discarded on top of the soil.

One of the difficulties with soil aeration devices is that a substantialamount of soil, grass and roots in the form of cylindrical plugs areleft on top of the soil. These soil plugs must either be removed,allowed to decompose, or pulverized via mowing. Generally, the largerthe soil plugs, the longer it takes for the soil plugs to decomposenaturally.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective of a soil aerator device having a set ofaeration tines;

FIG. 2 is a top view of an aeration tine;

FIG. 3 is a side view of the aeration tine of FIG. 2;

FIG. 3 a is a front view of the aeration tine of FIG. 2;

FIG. 3 b is a back view of the aeration tine of FIG. 2;

FIG. 4 is a bottom view of the aeration tine of FIG. 2;

FIG. 5 is a partial side view showing the aeration tine of FIG. 2penetrating the soil;

FIG. 6 is a partial side view showing the aeration tine of FIG. 2partially rotated within the soil;

FIG. 7 is a partial side view showing the aeration tine of FIG. 2emerging from the soil;

FIG. 8 is a perspective view of an alternate aeration tine;

FIG. 9 is a top view of the aeration tine of FIG. 8;

FIG. 10 is an end view of the aeration tine of FIG. 8;

FIG. 11 is a side view of the aeration tine of FIG. 8;

FIG. 12 is a perspective view of yet another embodiment of an aerationtine;

FIG. 13 is a top view of the aeration tine of FIG. 12;

FIG. 14 is an end view of the aeration tine of FIG. 12;

FIG. 15 is a side view of the aeration tine of FIG. 12;

FIG. 16 is a perspective view of an aeration tine adapted for use onputting greens;

FIG. 17 is a top view of the aeration tine of FIG. 16;

FIG. 18 is an end view of the aeration tine of FIG. 16;

FIG. 19 is a side view of the aeration tine of FIG. 16;

FIG. 20 depicts a golf course green that has been aerated with theaeration tine of FIG. 16; and

FIGS. 21-24 depict the planetary motion of arcuate tines in certainembodiments.

FIGS. 25-26 depict a top view and a side view, respectively, of anotherembodiment of an aeration tine.

SUMMARY

A soil aeration device may include a plurality of arcuate blades mountedto an assembly adapted to rotate and translate the blades proximate aground surface, thereby forming aeration pockets in the soil. In certainembodiments, the arcuate tines penetrate and fracture the soil whileminimizing the amount of soil lifted from the pocket deposited on thetop of the soil. In various embodiments, a planetary gear assemblyimparts to the tine a translational and rotational movement whichcreates a fractured pocket in the soil while minimizing the amount ofsoil lifted from the pocket and deposited on the surface of the soil. Instill other embodiments, the arcuate tine may have mounted thereon acoring tube that cuts and removes a plug from the pocket formed in thesoil.

The apparatus described herein may provide one or more of the followingadvantages. In certain embodiments, the soil aeration device enables agrassy area such as a golf course fairway to be aerated without thedeposition of the plugs or significant amounts of soil on the grass,thereby permitting use of the fairway immediately after aeration withoutthe need to remove or mow soil plugs or otherwise treat the area. Insome embodiments, the translational and rotational movement imparted toan arcuate coring tine minimizes the size of the aperture cut in thesoil and the amount of soil lifted from the aeration pocket anddeposited on the surface of the ground.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages of the invention will be apparent from the description anddrawings, and from the claims.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 is a perspective view of a pull type soil aeration device 10having a frame 11 supported by a pair of wheels 12. A gear mechanism 13,which is connected to the power take off shaft of a tractor (not shown),rotates the tine holders 14 which contain a set of soil aeration tines15. In the embodiment shown the aeration tines are located on parallelmembers and rotate in an epicycle or planetary manner. A soil aerationdevice providing planetary motion is more fully described in Bjorge U.S.Pat. No. 5,469,922 titled Soil Aerator issued Nov. 28, 1995 and isincorporated herein by reference.

FIG. 2 shows a top view of soil aeration tine 15 capable of bothfracturing and removing soil. Soil aeration tine 15 comprises anelongated member 20 having a central axis 19. Elongated member 20 has afirst section 22 terminating in an apex end 23 and a second section ormounting end 21 for mounting elongated member 20 on a soil aerationdevice. Mounted to elongated member 20 is a cylindrical soil cuttingtube 25 which is positioned rearwardly or aft of apex end 23 so thatwhen apex end 23 of elongated member 20 is axially driven into a patchof soil the apex end 23 of elongated member 20 penetrates the patch ofsoil before the soil cutting tube 25 engages the soil. As the firstsection 22 penetrates the soil it fractures the soil to form a partialsoil aeration pocket. Next, the soil 20 cutting tube 25 which ispositioned axially rearwardly of the apex 23 and has an annular cuttingedge 25 c and a conically tapered surface 25 a engages the soil aft ofthe apex end and proximate the soil aeration tine 15 to cut a plug ofthe soil free of the soil. Thus the fracturing of the soil occurs in thesoil around the lower portion of the hole and both fracturing and soilremoval occurs in the soil zone proximate the cutting tube which resultsin a soil aeration pocket in the soil where the soil aeration pocket islarger than the soil plug cut free of the soil and also without the soilcompaction that would occur if a spike were driven downward into thesoil.

FIG. 3 shows a side view of soil aeration tine 20 illustrating a portionof a divergent soil fracturing section 22 which includes an upwardlycurving soil fracturing face 20 a and an upwardly curving soilfracturing face 20 b that terminates at apex end 23. FIG. 3 a shows theopposite side of soil aeration tine 15 illustrating the other side ofthe divergent soil fracturing section 22 which includes identicalupwardly curving soil fracturing faces 20 c and 20 d that terminates atapex end 23. A soil lifting face 24 extends laterally from side-to sideof soil aeration tine 15. The soil lifting face 24 forms a scoop orspade so that when the soil aeration tine is rotationally removed fromthe soil the soil face 24 can lift or scoop soil from the soil aerationpocket.

The soil cutting tube 25 has a leading and annular cutting edge 25 cthat diverges outwardly along annular face 25 a to the cylindricalshaped soil cutting tube 25. The cutting edge 25 c of cutting tube 25 ispositioned a distance L rearward of the apex end 23 of soil aerationtine 15 to enable the soil fracturing section 22 to penetrate andfracture the soil before the soil aeration tube cuts a soil plug free ofthe soil. In the embodiment shown the soil cutting tube is positioned atleast one and one half inches rearward of the apex end to ensure thatthe length of the soil plug is kept to a minimum. On the other hand thesoil cutting tube should extend sufficiently far along elongated member20 so as to ensure that one can cut through the top layer of grass andsoil. Thus, in the embodiment shown in the drawings the end of the tine15 lacks an end coring device.

FIG. 3 b shows a back view of soil aeration tine 15 with a first line 31extending outward from the central axis 19 of elongated member 20 and asecond line 30 extending outward from the geometric center of cuttingtube 25 with the distance between the centers indicated by the dimensionx. That is, FIG. 3 b illustrates that the cutting tube is laterallyoffset from the elongated member 20 so that cutting tube 20 andelongated member 20 enter the soil in a side by side condition.

FIG. 4 is a bottom view of soil aeration tine 15 illustrating that thesoil fracturing faces 20 a and 20 c extend axially along elongatedmember 20 and terminate at apex end 23. Thus the under side of aerationtine 15 presents soil fracturing surfaces 20 a and 20 c while the topside of soil aeration tine 15 presents the latterly offset andrearwardly positioned cutting tube 25 for cutting the soil to remove aplug of soil and grass.

FIG. 5 is a partial schematic illustrating how soil aeration tine 15penetrates a patch of soil 40 at an acute angle φ with respect to thetop soil. In the first step the soil aeration soil fracturing surfaces20 a, 20 b on one side of elongated member 20 and the soil fracturingsurfaces 20 c and 20 located on the opposite side of the elongatedmember penetrate the soil with the soil fracturing surfaces entering thesoil at an acute angle causing the soil 40 proximate the soil aerationtine 15 to fracture upward rather than compact. That is the acute anglepenetration of the soil fracturing surfaces with the fracturing surfacesfacing upward produces an upward component that forces the soil upward.As the soil can fracture and move upward the resistance to soilcompaction above the soil aeration tine 15 is less than the resistanceto soil compaction in the lateral direction. That is, lateral displacingsoil produces increased soil compaction since the soil must compactagainst itself. Thus avoiding direct lateral compaction inhibits soilcompaction. At the same tine the soil fracturing faces fracture theportion of the soil located ahead of the soil aeration tine the cuttingedge 25 c, which trails the apex end 23, cuts a soil plug free of thesoil. In the embodiment shown the cutting edge 25 c extendssubstantially perpendicular to soil aeration tine 15 to enable the soilaeration tube 25 to capture a soil plug aft of the apex end 23 as thesoil aeration tine 15 is driven axially into the soil. It should bepointed out that although multiple soil fracturing faces are shown it isenvisioned that only a single soil fracturing surface could be used.

FIG. 6 illustrates the step when the soil aeration tine is rotated in aclockwise direction as the tine is being moved forward. This rotationalaction results in an aeration pocket 41 being formed in the region firstpenetrated by the soil aeration tine.

FIG. 7 illustrates the further enlargement of the soil aeration pocket41 as the soil aeration tine 15 continues in a compound motion as aresult of the planetary action that drives the tine rearward during therotation of the support mechanism and forward due to the pulling of thesoil aeration device and the rotation of the aeration tine. As a result,the compound rotation causes the soil aeration tine top face 24 to liftor scoop soil from the aeration pocket while a cut soil plug 42 is heldin cutting tube 25 to be disposed of on the ground when the soilaeration tube 25 exits the soil. The result is that one can form a soilaeration pocket 41 with a minimum of soil compaction and a minimum ofdisplaced soil as the soil aeration tine with the aft cutting tuberemoves a soil plug of substantially smaller volume than a soil aerationtube located on an apex end of a soil aeration tube. Consequently, lesssoil is left on top of the soil since the soil plugs formed by thepresent method are smaller than soil plugs formed by the end coremethod. Yet at the same tine the aeration holes 41 formed in the soilare as large or larger than holes formed by a conventional cylindricalcutting tubes.

Thus the method of making a soil aeration hole 41 comprises the step ofextending an elongated member 20 having a lateral face 24 on one sideand a soil diverging section formed by faces 20 a and 20 c on the otherside into the soil to fracture the soil proximate the diverging faces.In addition, one cuts a soil plug free of the soil with the soilaeration tube 25 by cutting the soil plug from the soil located rearwardand lateral of the diverging faces 20 a and 20 c. By rotationallyremoving the elongated member 20 one can free the soil plug and form asoil aeration hole 41 having a top opening smaller than a bottom openingas shown in FIG. 7. Also by rotationally removing the elongated member20 with the apex end 23 and lifting surface 24 one can partially scoopout soil with the soil lifting face 24 on the elongated member.

In the embodiments shown the soil cutting tube 25 has an externaldiameter larger than the external diameter of the aerator tine.Although, it is submitted that the diameter of the soil cutting tube 25can be governed by other factors such as soil types and soil conditions.

Thus the soil aerator tine 15 can include at least one soil fracturingface in a diverging section 22 which diverges in a direction rearwardfrom an apex end 23 on soil aerator tine 15 and in a direction away froma lifting face 24 on soil aerator tine 15. The soil aeration device 15illustrated in FIG. 3 a shows two soil fracturing faces 20 a and 20 csymmetrically positioned around a central axis 19 extending through thesoil aeration tine elongated member 20. A review of FIG. 3 a shows thatapex end 23 on soil aeration tine 15 is located lateral of the centralaxis 19 extending through the soil aeration tine 15. By having the soildiverging faces forming an off center apex 23 on one side of the soilaeration tine 15 the soil against the soil face 24 is penetrated withoutcompaction while the soil above the soil aeration fracture faces isforced away from the soil aeration tube. When the soil aeration tube isdriven at an acute angle into the soil the diverging fracturing surfacesmove the soil upward which fractures the soil without compacting thesoil.

FIGS. 8-11 depict an aeration blade 80 adapted for use in connectionwith the above-described aeration device 10. The blade 80 functionssimilarly to the aeration tine 15 discussed above, except that it doesnot cut and remove a plug of soil. The arcuate tine 80 penetrates thesoil as shown and described in connection with FIGS. 5-7, but becausethis blade lacks the soil cutting tube 25, no plug is removed from thesoil and deposited on the surface of the aerated turf. Rather, as theaeration tine 80 pivots in the motion shown in FIGS. 5-7, the arcuateend 81 of the aeration tine 80 cuts an aeration groove having a longerdimension in the direction of the cut, which provides a degree ofaeration comparable to that provided by aeration tine 15.

Moreover, turf aerated with tine 80 will not be littered with aerationplugs. As shown in FIG. 20, the surface 200 of the aerated turf remainssubstantially uniform. The aeration pockets 201 are visible, but nosignificant amount of soil has been deposited on the grass surface 200.Accordingly, the turf need not be further treated (as by mowing) beforereceiving approach shots or serving as a putting surface. The aerationtine 80 can thus be advantageously implemented to significantly reducemaintenance expenditures and virtually eliminate course downtime causedby aeration procedures.

Returning to FIGS. 8-11, the aeration blade 80 has a tip 82, concaveedge 83, and convex edge 84. The cavity 85 is adapted to be receivedonto a mounting element (not shown) protruding from tine holders 14 ofthe soil aeration device 10. The blade 80 may be made of high strengthsteel, metal alloys, composites, hard polymeric materials, or othersuitable materials. The cavity 85 may include threads, keys, detents,cross-drilled tapped holes for set screws, or other suitable structurethat cooperates with the mounting elements on tine holders 14 tosecurely and releasably hold blades 80. Releaseable mountingconfigurations advantageously facilitate removal of blades 80 forsharpening or replacement. The aeration tine 80 of FIGS. 8-11 has awidth 82 of approximately 7/16″.

The aeration tines of FIGS. 12-15 are similar to the tine of FIGS. 8-11,except that the tine of FIGS. 12-15 has a width 122 of approximately5/16″. The tine of FIGS. 16-19 has a width 162 of approximately ⅛″ andis adapted for aeration of surfaces which must remain particular flatand even after aeration, such as putting greens.

The operation of the arcuate aeration blades are shown in more detail inFIGS. 21-24. With reference to FIG. 21, an arcuate aeration blade 90penetrates soil 89 in a downward, clockwise motion 92. As the tractorproceeds in the direction shown by arrow 94, the planet gear (not shown)that drives the blade 90 rotates in clockwise direction (as shown byarrow 92) while being driven in a counterclockwise planetary direction(as indicated by arrow 91). As the tractor continues in the direction ofarrow 94, the blade 90 translates in the direction of arrow 91 whilecontinuing to rotate in the direction indicted by arrow 92, thus carvingan aeration pocket and causing soil fractures 93. Optionally, the blade90 can be mounted in the opposite direction, such that its longer bladeedge end faces in direction 94. Such an arrangement can be usefullyemployed to, for instance, lift soil from the aeration pocket, therebyincreasing the pocket's size.

FIGS. 23-24 depict an embodiment in which the planetary motion isreversed relative to that shown in FIGS. 21-22. The blade 98 plungesdownward into the soil 89 as it translates in the direction of arrow 96and rotates in a counter-clockwise direction, as indicated by arrow 97.As the tractor proceeds in the direction of arrow 95, the blade 98continues to translate and rotate in the aforementioned directions,thereby forming a pocket and soil fractures 99.

The blade 80 can be equipped with an aeration tube 25 on its trailing orleading edges, as shown in FIGS. 25-26. In such embodiments, the arcuateblade serves to fracture the soil which is compacted by the soilaeration tube 25.

Various additional modifications can be advantageously made to theapparatus described above in accordance with the teachings set forthherein. For instance, the edge on the concave side of the aeration blade80 can be replaced with a blunt surface. As noted above, the aerationblades tines can be oriented as shown in the figures, or they can berotated 180 degrees about the long axis of the blade. The planetary gearset can be modified to have any desired combination of clockwise andcounter-clockwise motions of the planet gear 13 a and sun gear 13 b sothat, for instance, both the translation and rotation of the blade arein a clockwise direction. The gear ratios and sizes can be freelymodified to create pockets having different profiles and fractures. Thetines can be grouped or staggered on the tine holders in any fashiondesired. For example, the tines can be grouped in pairs or tripletsalong the tine holders. The tines can also be disposed at a anglerelative to the vertical plane defined by the pocket shown in FIGS.21-24 to accomplish a different type of soil fracturing.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.

1. A method of aerating a soil surface, comprising: urging a pluralityof aeration tines in a compound motion including a rotational motionabout a first axis and an revolving motion about a second axis, eachaeration tine including: a proximal portion that is substantiallylongitudinally straight and comprises an adapter to secure the tine to atine holder member, and a curved blade portion extending distally fromthe proximal portion and including a concave blade edge and anoppositely disposed convex blade edge that extend generallylongitudinally toward a distal tip portion; penetrating a soil surfacewith the plurality of aeration tines to form aeration pockets in thesoil surface, the curved blade portion of each aeration tine fracturingsoil as it is urged in the compound motion.
 2. The method of claim 1,wherein each tine forms a slit in the soil surface and a pocket underthe soil surface without lifting substantial amounts of subterraneansoil onto the soil surface.
 3. The method of claim 2, wherein the slithas a first length and the pocket has a second length, said first lengthbeing smaller than said second length.
 4. The method of claim 1, whereinthe compound motion is imparted by a planetary gear assembly, therevolving motion being imparted by a revolving movement of a planet gearrelative to a sun gear and the rotational motion being imparted byrotational movement the planet gear about an axis of the planet gear. 5.The method of claim 1, wherein each aeration tine simultaneously removesa soil plug proximate the pocket.
 6. The method of claim 1, wherein whenthe curved blade portion is urged in the compound motion through thesoil surface, the convex blade edge moves through the soil and fracturesthe soil.
 7. The method of claim 1, wherein the adapter of each aerationtine comprises a threaded cavity.
 8. The method of claim 1, wherein theproximal portion of each aeration tine includes a substantiallycylindrical portion that extends in a longitudinal direction.
 9. Themethod of claim 8, wherein the substantially cylindrical portion has alateral thickness that is substantially greater than the lateralthickness of the curved blade portion.
 10. An aeration device,comprising: a tine holder member; a plurality of aeration tines mountedto the tine holder member, each aeration tine including: a proximalportion that is substantially longitudinally straight and comprises anadapter to secure the tine to the tine holder member, and a curved bladeportion extending distally from the proximal portion and including aconcave blade edge and an oppositely disposed convex blade edge thatextend generally longitudinally toward a distal tip portion; a gearassembly adapted to urge the plurality of aeration tines in a compoundmotion through a soil surface, the compound motion including arotational motion about a first axis and an revolving motion about asecond axis.
 11. The aeration device of claim 10, wherein when thecurved blade portion is urged in the compound motion through the soilsurface, the convex blade edge moves through the soil and fractures thesoil.
 12. The aeration device of claim 11, wherein said motion of thecurved blade portion is operable to form a slit in a soil surface and apocket under the soil surface which is larger than the slit.
 13. Theaeration device of claim 10, wherein the curved blade portion has athickness which is substantially less than the thickness of the proximalportion of the aeration tine.
 14. The aeration device of claim 10,wherein the adapter of each aeration tine comprises a threaded cavity.15. The aeration device of claim 10, wherein the proximal portion ofeach aeration tine includes a substantially cylindrical portion thatextends in a longitudinal direction.
 16. The aeration device of claim15, wherein the substantially cylindrical portion has a lateralthickness that is substantially greater than the lateral thickness ofthe curved blade portion.
 17. The aeration device of claim 10, whereinthe gear assembly includes a planet gear and a sun gear, and the tineholder member is coupled to the planet gear.
 18. The aeration device ofclaim 17, wherein the planetary gear imparts the compound motion to theaeration tines.
 19. The aeration device of claim 10, wherein eachaeration tine further includes an aeration tube laterally offset fromthe curved blade portion.